Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.1 (Mg2+-ATPase)
 1,484 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An X-linked recessive disease is reported in a large pedigree. The disease is characterised by a triad of dilated cardiomyopathy, neutropenia and skeletal myopathy. The untreated patients, all boys, died in infancy or early childhood from septicemia or cardiac decompensation. Ultrastructural abnormalities were observed in mitochondria in cardiac muscle cells, neutrophil bone marrow cells and to a lesser extent (0-9%) in skeletal muscle cells. Membrane-bound vacuoles were seen in neutrophil bone marrow cells. Intramuscular fat droplets were increased in type I skeletal muscle fibres. An affected patient had intermittent lactic acidemia, borderline low plasma carnitine, the latter decreasing during periods of illness, and low muscle carnitine (27% pretreatment; 35-40% posttreatment). While on treatment with oral carnitine he had less weakness and no cardiac complaints, but his neutropenia was not affected. Respiratory chain abnormalities were observed in this patient's isolated skeletal muscle mitochondria. These were: (1) diminished concentrations of cytochromes c1 + c, b and aa3 to 29, 47 and 64% of the averaged controls, and (2) a lowered P:0 ratio for oxidation of ascorbate + TMPD, with diminished uncoupler stimulated Mg2+-ATPase activity. Muscle AMP deaminase was deficient (5 resp. 17%). Only one previous report (Neustein et al. 1979) on X-linked mitochondrial cardiomyopathy exists, which probably refers to the same entity. Biochemical studies and haematological abnormalities (neutropenia) are reported for the first time.
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PMID:An X-linked mitochondrial disease affecting cardiac muscle, skeletal muscle and neutrophil leucocytes. 614 97

In pursuit of the characterization of the recently discovered flippase mode of operation of the anion transporter (band 3, AE1) of the human erythrocyte membrane, the transbilayer translocation (flip) of a fluorescently labeled, membrane-intercalated long-chain alkyl phosphate, 10-(alpha-napthyl)-1-decyl-phosphate (NDP) was investigated. In contrast to the alkyl sulfonates and esters of phosphatidic acid studied as yet, NDP moves exclusively via band 3. NDP is, however, dephosphorylated at the inner membrane surface by a cytoplasmic phosphatase likely to interact specifically with endofacial membrane structures of the erythrocyte. This phosphatase shares characteristic inhibitor sensitivities with protein tyrosine phosphatases present in the erythrocyte interior. Vanadate as an inhibitor of NDP dephosphorylation provided a means to study the kinetic properties and patterns of inhibition (by inhibitors of anion exchange) and stimulation (by proteolysis of band 3 and aliphatic alcohols) of the flip of NDP. NDP is also an inhibitor of the exchange of hydrophilic anions via band 3, while hydrophilic anions interfere with the flip of NDP. The results are compared with the characteristics of the flip, via Band 3, of other amphiphilic anions and of the exchange of hydrophilic anions. Attempts are presented to understand the low flip rate of long-chain amphiphilic anions on the basis of their molecular properties and the thermodynamics of the "transition state" of the flip process.
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PMID:Band 3-mediated flip-flop and phosphatase-catalyzed cleavage of a long-chain alkyl phosphate anion in the human erythrocyte membrane. 974 99

Lipopolysaccharide (LPS) is the major component of the outer leaflet of the outer membrane of Gram-negative bacteria. The LPS molecule is composed of two biosynthetic entities: the lipid A--core and the O-polysaccharide (O-antigen). Most biological effects of LPS are due to the lipid A part, however, there is an increasing body of evidence also with Yersinia indicating that O-antigen plays an important role in effective colonization of host tissues, resistance to complement-mediated killing and in the resistance to cationic antimicrobial peptides that are key elements of the innate immune system. The biosynthesis of O-antigen requires numerous enzymatic activities and includes the biosynthesis of individual NDP-activated precursor sugars in the cytoplasm, linkage and sugar-specific transferases, O-unit flippase, O-antigen polymerase and O-chain length determinant. Based on this enzymatic mode of O-antigen biosynthesis LPS isolated from bacteria is a heterologous population of molecules; some do not carry any O-antigen while others that do have variation in the O-antigen chain lengths. The genes required for the O-antigen biosynthesis are located in O-antigen gene clusters that in genus Yersinia is located between the hemH and gsk genes. Temperature regulates the O-antigen expression in Y. enterocolitica and Y. pseudotuberculosis; bacteria grown at room temperature (RT, 22-25 degrees C) produce in abundance O-antigen while only trace amounts are present in bacteria grown at 37 degrees C. Even though the amount of O-antigen is known to fluctuate under different growth conditions in many bacteria very little detailed information is available on the control of the O-antigen biosynthetic machinery.
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PMID:Molecular genetics, biochemistry and biological role of Yersinia lipopolysaccharide. 1275 56

B lymphopoiesis begins in the fetal liver, switching after birth to the bone marrow, where it persists for life. The unique developmental outcomes of each phase are well documented, yet their molecular requirements are not. Here we describe two allelic X-linked mutations in mice that caused cell-intrinsic arrest of adult B lymphopoiesis. Mutant fetal liver progenitors generated B cells in situ but not in irradiated adult bone marrow, which emphasizes a necessity for the affected pathway only in the context of adult bone marrow. The causative mutations were ascribed to Atp11c, which encodes a P4-type ATPase with no previously described function. Our data establish an essential, cell-autonomous and context-sensitive function for ATP11C, a putative aminophospholipid flippase, in B cell development.
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PMID:The P4-type ATPase ATP11C is essential for B lymphopoiesis in adult bone marrow. 2182 67